As disclosed in the Japanese Patent Application Publication No. 2004-10220, conventionally, in image forming apparatus there is known a paper sheet receiving tray provided an extension member slidably or rotatably mounted on an end of the tray for expanding the paper sheet receiving surface, in order that when a lengthy sheet is loaded thereon, the extension member is able to appropriately support the lengthy sheet without the tip of the sheet hanging down.
As an example of such an extension member, a U-shaped extension member is quoted. The U-shaped extension member is pivotally mounted to the try by inserting pivot shafts provided on both ends of the extension member into two shaft bearing holes provided on an end of the tray. Since such an extension member is mounted by the pivot shafts at the two ends of the extension member being simply inserted into the shaft bearing holes, there is a feature that the extension member easily disengages from the tray. Accordingly, also when stiff external force is applied to the extension member, the extension member separates from the tray before wrecking. As a result, the extension member can be prevented from wrecking.
In order to prevent wrecking of the U-shaped extension member mounted to the tray of an image forming apparatus when stiff external power is applied to the extension member, the extension member is structured to disengage from the tray before wrecking. However, there presents a problem that the extension member disengages from the tray on the way of rotating the extension member by hand, and thus letting hard to handle.